Posterior capsulotomy using laser techniques

ABSTRACT

A system and method are provided for removing a natural lens and inserting an Intraocular Lens (IOL) into the lens capsule of an eye. Specifically, this is accomplished by inserting the IOL through an opening on the posterior capsule that is created using a focused laser beam. The system includes a laser unit, a detector for creating images of the interior of the eye, and a computer that controls the cooperative functions of the detector and the laser unit. Based on images of the posterior capsule provided by the detector, the computer is used to control movements of the focal point through tissue of the posterior capsule to perform Laser Induced Optical Breakdown (LIOB) on posterior capsule tissue. The result is a laser capsulotomy that creates an opening through the posterior capsule allowing the natural lens to be removed and the IOL to be implanted.

This application is a divisional of application Ser. No. 14/412,168,filed Dec. 30, 2014, which is currently pending. Application Ser. No.14/412,168 is a 371 of International Application No. PCT/US2013/031394,filed Mar. 14, 2013, which is expired and which claims the benefit ofU.S. Provisional Patent Application Ser. No. 61/671,312, filed Jul. 13,2012, which is expired.

FIELD OF THE INVENTION

The present invention pertains generally to ocular laser surgery. Moreparticularly, the present invention pertains to capsulotomy proceduresthat employ a femtosecond laser. The present invention is particularly,but not exclusively, useful for performing a posterior capsulotomyprocedure to insert an Intraocular Lens (IOL) into the lens capsule ofan eye.

BACKGROUND OF THE INVENTION

A common treatment for a cataract involves removal of the diseased lensfrom a patient's eye followed by replacement with an Intraocular Lens(IOL). Originally, the entire lens and capsule were removed andreplaced. More modernly, the lens is removed from the capsule, in situ,and the new IOL is inserted into the capsule.

In a typical cataract procedure, access to the lens is obtained and thelens is fragmented and/or emulsified. For example, the lens can beemulsified using a traditional ultrasonic handpiece (a process known as“phacoemulsification”), or, more modernly, the lens can be fragmentedusing a femtosecond laser. Once fragmented or emulsified, the lensmaterial can be removed from the capsule, for example, by aspirating thematerial using an aspiration needle. Once the lens material has beenremoved, an IOL can be inserted into the remaining portion of the lenscapsule.

To perform the procedures described above, an opening in the lenscapsule is required. Two possibilities for this opening include ananterior capsulotomy in which an opening is made on the anterior surfaceof the lens capsule and a posterior capsulotomy in which an opening ismade on the posterior surface of the lens capsule. Typically, for ananterior capsulotomy, the surgeon gains access to the capsule and lensthrough incisions that are made on the cornea or limbus. However, theseincisions can adversely affect the refractive properties of the eye,including the inducement of undesirable astigmatism.

Another drawback associated with a typical anterior capsulotomyprocedure involves anatomical considerations. In more detail, access tothe anterior capsule surface necessarily involves transit through therelatively small anterior chamber of the eye. Unfortunately, there are anumber of surgical problems associated with passing tools, such as thephacoemulsification probe and aspiration needle, through the smallanterior chamber of the eye. Moreover, the anterior capsulotomyprocedure can disturb other fragile anatomical structures that areanterior to the crystalline lens.

Unlike the anterior capsulotomy, access for a posterior capsulotomy canbe obtained using incisions through the sclera on the side of the eye.These incisions do not, in general, affect the refractive properties ofthe eye like the incisions described above that are made on the corneaor limbus. In addition, there is more operating room on the posteriorside of the crystalline lens than the small anterior chamber of the eye.And, in many instances, additional room for tool manipulation can bemade on the posterior side of the crystalline lens by performing apartial vitrectomy.

Another advantage of a posterior capsulotomy is that the optical barrier(e.g. the anterior surface of the capsule) is maintained intact during asurgical procedure. Lastly, the use of a posterior capsulotomy canprovide flexibility for combining the capsulotomy procedure with othersurgical procedures in the back of the eye.

In light of the above, it is an object of the present invention toprovide a system and method for performing a posterior capsulotomy.

Another object of the present invention is to provide a system andmethod for performing a posterior capsulotomy procedure to accommodatethe insertion of an Intraocular Lens (IOL) into the lens capsule of aneye.

Still another object of the present invention is to provide a system andmethod for performing a posterior capsulotomy procedure using lasertechniques which is simple to implement and is relatively costeffective.

SUMMARY OF THE INVENTION

In accordance with the present invention, a system and method areprovided for inserting an Intraocular Lens (IOL) into the lens capsuleof an eye. Specifically, this is accomplished by inserting the IOLthrough an opening that is created through the posterior capsule of theeye. In overview, the system includes a detector for creating images ofthe interior of the eye, and it includes a laser unit for generating andfocusing a laser beam to a focal point. The system further includes acomputer that controls the cooperative functions of the detector and thelaser unit.

For an operation of the present invention, the computer processes imagesthat are provided by the detector. Specifically, these images are oftissue inside the eye and their processing by the computer isaccomplished to establish an accurate location for the posterior capsuleof the eye. As envisioned for the present invention, the detector ispreferably an imaging unit that employs imaging techniques selected froma group comprising Optical Coherence Tomography (OCT), Scheimpflugimaging, confocal imaging, two-photon imaging, laser (optical) rangefinding and acoustical imaging.

In addition to receiving images from the detector, the computer alsooperates the laser unit to generate and focus a laser beam. In detail,the laser beam is preferably a pulsed laser beam wherein each pulse hasa duration less than one millisecond. Furthermore, it is necessary thatthe energy at the focal point of the laser beam be capable of performingLaser Induced Optical Breakdown (LIOB) of tissue of the posteriorcapsule.

Based on images of the posterior capsule that have been provided by thedetector (imaging unit), the computer is used to control movements ofthe focal point through tissue of the posterior capsule. As indicatedabove, this is done for the purpose of performing Laser Induced OpticalBreakdown (LIOB) on tissue of the posterior capsule. As envisioned forthe present invention, the condition of tissue of the posterior capsuleis of interest only insofar as it may affect the laser operation. Stateddifferently, the present invention pertains regardless whether theposterior capsule is initially intact, or somehow torn. In either case,the intent here is to create an opening through the posterior capsulethat can be used for inserting the IOL into the lens capsule.Importantly, in this process, the opening is dimensioned and customizedto receive a specific IOL into the lens capsule via the opening.

In accordance with a methodology for the present invention, thecrystalline lens of an eye is prepared for its removal from the lenscapsule at an appropriate time in the particular procedure. As will beappreciated by the skilled artisan, preparation of the lens can be donein any of several different ways that are well known in the pertinentart. For example, techniques such as hydrodissection andphacoemulsification may be used for this purpose. Preferably, lasertechniques such as disclosed in U.S. application Ser. No. 13/436,352,which was filed on Mar. 30, 2012 for an invention entitled “System andMethod for Performing Lens Fragmentation,” can be useful for this samepurpose.

At an appropriate time in the procedure, Laser Induced Optical Breakdown(LIOB) is performed on tissue of the posterior capsule of the eye tocreate a section of separated tissue. In effect, this involves a lasercapsulotomy that creates an opening through the posterior capsule, intothe lens capsule of the eye. The section of separated tissue is thenremoved from the lens capsule to establish the opening. As envisionedfor the present invention, this removal of the separated tissue sectionwill be accomplished by first incising the sclera to establish an accessport to the vitreous body of the eye. A probe can then be advancedthrough the access port for engagement of the probe with the section ofseparated tissue. After the probe has engaged with the separated sectionof tissue, the separated section of tissue can be removed from the eyeby the probe to establish the opening.

Once an opening has been established through the posterior capsule ofthe eye, the crystalline lens of the eye can be extracted (removed) fromthe lens capsule of the eye. The extracted lens can then be removed fromthe eye through the access port that has been created through thesclera. Specifically, this may include removing the whole lens throughthe scleral incision using mechanical cutters and macelators such asscissors, lassos, guillotine cutters, cautery devices, aqua-jets,ultrasonic blades, a combination of a laser and another extractiondevice, or any other device or technique sufficient to remove the lens.

Once the crystalline lens has been extracted (removed), an IOL can beintroduced through the sclera and inserted through the opening in theposterior capsule to replace the extracted lens. As an additionalfeature of the present invention, LIOB marks can be established on thelens capsule during the procedure to assist in aligning the IOL in thelens capsule. Such feature may be particularly useful for properlyorienting a toric IOL that is to be used for the correction ofastigmatism.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of this invention, as well as the invention itself,both as to its structure and its operation, will be best understood fromthe accompanying drawings, taken in conjunction with the accompanyingdescription, in which similar reference characters refer to similarparts, and in which:

FIG. 1 is a schematic presentation of components for the system of thepresent invention;

FIG. 2A is a cross section view of the anterior portion of an eyeshowing the removal of tissue from the posterior capsule of the eye tocreate an opening into the lens capsule; and

FIG. 2B is a cross section view of the anterior portion of the eye asseen in FIG. 2A, showing the insertion of an Intraocular Lens (IOL)through the opening into the lens capsule of the eye, after thecrystalline lens of the eye has been removed from the lens capsule.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring initially to FIG. 1, a system in accordance with the presentinvention is shown and is generally designated 10. As shown, the system10 includes a laser unit 12 and a computer 14. As shown, the computer 14is connected with the laser unit 12 for the purposes of guiding andcontrolling the movement of a laser beam 16 that is generated andfocused by the laser unit 12. Necessarily, the laser unit 12 is of atype that generates a pulsed laser beam 16 which is capable ofperforming Laser Induced Optical Breakdown (LIOB) on sub-surfaceanatomical tissue. Preferably, the laser beam 16 will have laser pulseswith pulse durations in the femtosecond range.

FIG. 1 also shows that the system 10 can include a detector 18 forcreating images of the interior of the eye 20. For example, the detector18 can include an imaging unit that employs imaging techniques such asOptical Coherence Tomography (OCT), Scheimpflug imaging, confocalimaging, two-photon imaging, laser (optical) range finding andacoustical imaging. As shown, the computer 14 is connected to thedetector 18 to receive and process image data from the detector 18 andcontrol the operation of the detector 18. More specifically, images oftissue inside the eye 20 can be processed by the computer 14 toestablish an accurate location for the crystalline lens 22 and posteriorcapsule 24 of the eye 20.

FIG. 2A illustrates a procedure for creating a section of separatedtissue 26 and removing the tissue 26 from the posterior capsule 24 ofthe eye 20 to create an opening 28 into the posterior capsule 24. Forthis procedure, images of the posterior capsule 24 (FIG. 1) are providedby the detector 18 to the computer 14 which uses the image data tocontrol movements of the focal point through tissue of the posteriorcapsule 24. As this is done, Laser Induced Optical Breakdown (LIOB)occurs on tissue of the posterior capsule 24 to create a section ofseparated tissue 26. Once the separated tissue is removed, an opening 28is established through the posterior capsule 24 that can be used forremoving the lens 22 and/or inserting an IOL 30 (FIG. 2B) into the lenscapsule 31. For this process, the opening 28 can be dimensioned andcustomized to allow a specific IOL 30 (FIG. 2B) to pass through theopening 28 and be implanted into the lens capsule 31.

Continuing with FIG. 2A, it can be seen that the separated tissue 26 canbe removed from the eye 20, by first incising the sclera 32 to establishan access port 34 to the vitreous body 36 of the eye 20. As shown, aprobe 38 can then be advanced through the access port 34 for engagementof the probe 38 with the section of separated tissue 26. After the probe38 has engaged with the separated section of tissue 26, the separatedsection of tissue 26 can be removed from the eye 20 by the probe 38 (inthe direction of arrow 40) and through access port 34 to establish theopening 28. Once an opening 28 has been established through theposterior capsule 24 of the eye 20, as shown, the crystalline lens 22can be extracted from the lens capsule 31 and removed from the eye 20through the access port 34.

FIG. 2B shows that an IOL 30 can be introduced through the access port34 in the sclera 32 and inserted through the opening 28 (in thedirection of arrow 42 and into the lens capsule 31. As shown, probe 44can be used to place the IOL 30 into the lens capsule 31. As anadditional feature of the present invention, LIOB marks (not shown) canbe established on the lens capsule 31 during the procedure to assist inaligning the IOL 30 in the lens capsule 31. For example, these LIOBmarks may be used to properly orient a toric IOL (not shown) that is tobe used for the correction of astigmatism.

While the particular Posterior Capsulotomy Using Laser Techniques asherein shown and disclosed in detail is fully capable of obtaining theobjects and providing the advantages herein before stated, it is to beunderstood that it is merely illustrative of the presently preferredembodiments of the invention and that no limitations are intended to thedetails of construction or design herein shown other than as describedin the appended claims.

1. (canceled)
 2. (canceled)
 3. (canceled)
 4. (canceled)
 5. A computerprogram product for performing ophthalmic surgery inside an eye tocreate an opening through the posterior capsule of the eye for insertingan optical device into the lens capsule of the eye, wherein the computerprogram product comprises program sections for respectively: operating alaser unit to generate a pulsed laser beam; activating a detector createimages of the inside of the eye; controlling movements of the focalpoint of the laser beam through tissue of the posterior capsule based ondata from images of the inside of the eye to perform Laser InducedOptical Breakdown (LIOB) on tissue of the posterior capsule to create anopening into the lens capsule of the eye; and monitoring images of theinside of the eye during an extraction of the lens of the eye from thelens capsule of the eye through the opening in the posterior capsule toverify removal of the lens.
 6. The computer program product of claim 5further comprising a program section for preparing the lens of the eyefor removal from the posterior capsule prior to the extracting step. 7.The computer program product of claim 6 wherein preparing the lens forremoval is accomplished by a procedure selected from the groupconsisting of hydrodissection, phacoemulsification and lensfragmentation.
 8. The computer program product of claim 5 wherein theoptical device is an Intraocular lens (IOL).
 9. The computer programproduct of claim 8 further comprising a program section for establishingLIOB marks on the lens capsule to assist in aligning the IOL in the lenscapsule.
 10. The computer program product of claim 9 further comprisinga program section dimensioning the opening to receive a specific IOLinto the lens capsule via the opening.
 11. The computer program productof claim 5 further comprising program sections for: incising the sclerato establish an access port into the vitreous body of the eye; andadvancing a probe through the access port to extract the lens.